1 files changed, 43 insertions, 0 deletions
diff --git a/ast.h b/ast.h
new file mode 100644
index 0000000..67d6228
--- /dev/null
+++ b/ast.h
@@ -0,0 +1,43 @@
+#ifndef AST_H
+#define AST_H
+
+typedef enum {
+  NT_SKIP, NT_ASSIGN, NT_SEQ, NT_IF, NT_WHILE,
+  NT_INT, NT_VAR, NT_AOP, NT_BOP, NT_NOT, NT_ROP
+} NodeType;
+
+typedef enum { AOP_ADD, AOP_SUB, AOP_MUL } AOp;
+typedef enum { BOP_AND, BOP_OR } BOp;
+typedef enum { ROP_EQ, ROP_NE, ROP_LT, ROP_LE, ROP_GT, ROP_GE } ROp;
+
+typedef struct ASTNode {
+  NodeType type;
+  union {
+    int val;
+    char *var;
+    struct { struct ASTNode *var, *aexp; } assign;
+    struct {  struct ASTNode *exp1, *exp2; union { AOp aop; BOp bop; ROp rop; } op;} bin;
+    struct ASTNode *bexp;
+    struct { struct ASTNode *bexp, *s1, *s2; } cond;
+    struct { struct ASTNode *s1, *s2; } seq;
+  } u;
+} ASTNode;
+
+ASTNode *ast_skip(void);
+ASTNode *ast_assign(ASTNode *var, ASTNode *aexp);
+ASTNode *ast_seq(ASTNode *s1, ASTNode *s2);
+ASTNode *ast_if(ASTNode *bexp, ASTNode *s1, ASTNode *s2);
+ASTNode *ast_while(ASTNode *bexp, ASTNode *s);
+ASTNode *ast_int(int val);
+ASTNode *ast_var(char *var);
+ASTNode *ast_aop(AOp, ASTNode *aexp1, ASTNode *aexp2);
+ASTNode *ast_bop(BOp, ASTNode *bexp1, ASTNode *bexp2);
+ASTNode *ast_not(ASTNode *bexp);
+ASTNode *ast_rop(ROp, ASTNode *aexp1, ASTNode *aexp2);
+
+void exec_stmt(ASTNode *n);
+void free_ast(ASTNode *n);
+void env_print(void);
+
+#endif
+